UNLABELLED PREMISE OF THE STUDY One potential threat to rare species is genetic swamping caused by hybridization, but few studies have quantified this threat. Rhododendron cyanocarpum is a narrow endemic species that occurs sympatrically with potentially interfertile congeners throughout its range within Yunnan, China. We searched the entire distribution of R. cyanocarpum for hybrids and exa...

Frost resistance and ice nucleation temperatures of leaves, from bud swelling until after full expansion, were measured in situ for five major woody timberline species with recently developed field freezing equipment. Frost resistance determined in situ on leaves of attached twigs was significantly higher than values determined on detached leaves in laboratory tests (e.g., the temperature at wh...

Sustainable nutrient and water management are critical for optimizing the quality subsequent landscape performance of nursery plants. In this 2-year study, we investigated influence different nitrogen (N) rates [N-free fertilizer (0 N) or N-free plus 7 (0.5 14 (1.0 mg N per day from NH4NO3] irrigation frequencies volumes [once daily to 50% 100% container capacity (CC) twice with same total amou...

Grayanotoxins are known to occur in the honey produced from the nectar of Rhododendron ponticum growing on the mountains of the eastern Black Sea region of Turkey and also in Japan, Nepal, Brazil, and some parts of North America and Europe. Two cases of honey intoxication are presented here. Both of the patients experienced severe bradycardia and hypotension after ingestion of honey which was b...

Extracellular freezing results in cellular dehydration caused by water efflux, which is likely regulated by aquaporins (AQPs). In a seasonal cold acclimation (CA) study of Rhododendron catawbiense, two AQP cDNAs, RcPIP2;1 and RcPIP2;2, were down-regulated as the leaf freezing tolerance (FT) increased from -7 to approximately -50 degrees C. We hypothesized this down-regulation to be an adaptive ...

Rhododendron aureum Georgi is a perennial evergreen dwarf shrub that grows at all elevations within the alpine tundra of northern China. Previous research has investigated the plant communities of R. aureum; however, little information is available regarding interspecific competition and underground soil microbial community composition. The objective of our study was to determine whether the pr...

Synnemapestaloides rhododendri, the type species of the genus Synnemapestaloides, is a pathogen of Rhododendron brachycarpum. This fungus produces six-celled conidia with appendages at both end cells, and are generated by annellidic conidiogenous cells on the synnema. These conidial structures are similar to those of the genus Pestalotia. The monotypic genus Synnemapestaloides is currently clas...

Litter decomposition is an essential process in nutrient cycling terrestrial ecosystems. Phenolic acids have allelopathic effect on the natural regeneration of rhododendron forests, which was recently observed forests Southwest China. We investigated distribution phenolic and their relationship with soil nutrients during litter to provide a reference for subsequent artificial management forests...

The fastest way to create new azalea (Rhododendron simsii hybrids) cultivars is by making use of flower colour sports, which appear spontaneously on azalea plants. Unfortunately, there is still very little known on how bud sport induction occurs. Therefore, genes coding for two key enzymes of the azalea flavonoid biosynthesis pathway, chalcon synthase (chs) and dihydroflavonol 4-reductase (dfr)...